There’s a war going on around you. At your geedunk machine, your mess line, your shop, wherever you leave an open bag of potato chips. The foes have quietly penetrated your ship’s perimeter. Some even lie in wait in the folds of your rack, waiting to stab you and suck your blood.

They are parasites and scavengers that feast on sailors and their trash, and they can thrive in the cramped, moist confines of ships. If they’re not stopped immediately, they can quickly overwhelm their victims, namely you. And they have.

Navy records reveal that in recent years, a thousand cockroaches swarmed the frigate John L. Hall; a hundred roof rats ran wild in the attack submarine La Jolla; and bees built their hive in a helicopter aboard the amphibious assault ship Peleliu.

The Navy, fortunately, has a cadre of insect-spraying, trap-laying sailors on call in fleet concentration areas near you to confront the nastiest infestations.

“They call us bug chasers,” said Chief Hospital Corpsman (SW/AW) Rodney Lindsay, a seasoned preventive medicine technician who has dislodged cockroach colonies from a few dozen ships and commands during his 14 years of service. On one job — which they call a “TAV,” for technical assist visit — Lindsay saw nearly a thousand roaches aboard a dry-docked amphibious ship. He exterminated an infestation that had spread from the trash room and taken over the galley.

“At that stage, you’re kind of like Superman,” Lindsay said of the feeling of arriving on board to exterminate. “Like ‘Hey, we’ve been overran. We need some reinforcements.’”

Cockroaches are the fleet’s most common nuisance. These stowaways infest dozens of ships a year, Navy records reveal, sickening and disgusting sailors. Fortunately, they rarely carry the most pernicious diseases.

After so long fighting these crafty creatures that entrench into a ship’s filthiest bowels, Lindsay said he no longer finds them gross.

“When I first came on, I was” disgusted by them, he said. “But after dealing with it so long — you just know your opponent so well and you’re not intimidated by it anymore,” he said with a laugh.

There are many more pests that afflict sailors, according to infestation logs and reports Navy Times obtained via the Freedom of Information Act. But the most threatening pest is one that every sailor encounters, all the time.

“What’s the most hazardous pest? And most people would think, well, a snake or a scorpion or something that’s really nifty or nice-looking,” said Cmdr. Eric Hoffman, the entomologist who leads the Navy Entomology Center of Excellence. “But actually it’s the mosquito that kills the most people.”

Mosquitoes carry the deadly disease malaria, as well as many other serious illnesses, and frequently threaten sailors at forward-deployed bases, especially in Africa and tropical regions. They are not an issue in the fleet, however.

But tiny brown parasites are much more notorious and widespread.

Few things can spread a panic faster aboard a ship than a report of bedbugs. This reaction is out of proportion to how much harm they cause (little) or how frequently they infest ships. Only a handful of ships were infested in 2012, based upon the fact that the Navy Environmental and Preventive Medicine Unit in Hawaii logged only one case of confirmed bedbugs in the entire Pacific Fleet. (There are three NEPMUs to handle serious infestations and other health issues.) Ship’s docs are the first line of defense, but when they are overwhelmed, they resort to the NEPMU bug-chasers. And bedbugs are among their nastiest opponents.

“They are very, very difficult to get rid of,” testified Hospital Corpsman 1st Class (FMF/SW/AW) Mark Gornitzka, last year’s PMT of the year, who said he’d confronted “large outbreaks” as a tech on an aircraft carrier earlier in his 16-year career. “They can live for multiple months without a blood meal. So they can hide out and wait for that next blood meal and can sometimes repopulate after months.”

Then again, sometimes sailors bring it on themselves. During a deployment, one flight deck crewman came to the carrier’s medical bay with a case of biting mites, Gornitzka said. Down came another and another, each with bite marks up and down his arms. Mites are an unusual pest, and Gornitzka wanted to get to the source of what could be spreading the infestation.

The crew members obliged by bringing down the culprit: an adult pelican. It had flown aboard after a port visit. Wanting a pet, they nestled it into a nook in the flight deck spaces.

“There were just some type of biting mites that the bird had on it,” Gornitzka said, adding, “We got rid of the bird at the next port visit ... and treated the patients from there.”